Because of the current worldwide over supply of crude oil, natural gas, and similar hydrocarbonaceous fluids, it is well known that the production of hydrocarbonaceous fluids form certain low production wells has been shut-in because it is no longer economic to produce these wells. Often, such wells are termed "stripper wells" and typically produce less than ten barrels of oil per day.
If a particular well is shut-in for a sufficient length of time, it is often not economic thereafter to start up production from that well again because of the incursion of aqueous fluids, such as salt water, during the shut-in period. When this occurs the well is cemented in and abandoned at substantial extra cost to the owners, even though there is a substantial amount of oil or other hydrocarbonaceous fluid still present in the reservoir surrounding the wellbore that is to be plugged with cement and abandoned. For example, twenty to forty percent of the pore volume of a reservoir can still contain useful hydrocarbonaceous fluid which is desirably recovered if it can be recovered economically.
Thus, even though the well was producing economic volumes of hydrocarbonaceous fluid before shut-in, after being shut-in for a substantial time period, it can be uneconomic to start up production from that well again because the water/hydrocarbon ratio of fluids produced from the reservoir into the wellbore has, during shut-in, increased to a value where so much water is pumped along with the hydrocarbon that the production costs prevent start up and continued production of the well.
However, if the water/hydrocarbon ratio of fluids present in the wellbore and reservoir could be decreased to a value which rendered the produced hydrocarbonaceous fluid economically viable, then it is better not to plug and abandon the well, but rather merely to leave it shut-in until market forces are such that start up of production of the well once again becomes economically viable.